Cutaneous Leishmaniasis outbreaks and management

Abstract

‘Cutaneous Leishmaniasis’ (CL) term includes a broad range of clinical expressions, etiological agents of the genus Leishmania, and environmental and epidemiological scenarios, distributed mainly in the inter-tropical belt around the world. The outbreak events involve a couple of unexpected cases to more than 60,000 cases by year. There are ‘perfect waves’ or eco-epidemiological momenta of interwoven socio-economic, political and cultural, biological and physical causes, and also inter-linked consequences. However, we can figure out a typology of the outbreaks to think on the better strategies to control them, discriminating levels because in the large-long duration ones, climate change, economic trends or immune compromise by malnutrition, require actually structural changes. On the other hand, in space-time scales from foci up to individual exposure two mains processes could be discriminated: the human moving toward the primarily zoonotic cycle or the zoonotic cycle moving toward the humans. In the former case the contact could be: 1) Transient: soldiers, fleeing populations, illegal traffic, forest-related works as deforestation; 2) temporary: soldier, refugees and workers camps as gold miners settled on potential foci; 3) permanent: immigration of susceptible people, peripheral new neighborhoods (deforestation-peaks) or settlements in ‘low rent’ lands (unplanned urbanization-borders-new endemic areas). The zoonotic cycle toward human outbreaks, even if afterward the cycle become anthroponotic, are usually related to environment modification, vector-reservoir dispersion or exceptional population growth, and frequency of extreme climatic events. Many control measures were assayed for these scenarios as active surveillance, physical and chemical blocking or ‘barrier’ interventions, reservoir elimination directly or by food deprivation, although there are scarce rigorous impact evaluations. However, the better strategy to control outbreaks is to avoid them wherever possible, each past outbreak is a lesson to learn. Development, urbanization, military and law-enforcement projects should include CL epidemiological risk assessment with forecasting statistical modeling in time and space; the corporate and the state accountability should be explicitly stated and evaluated ‘a priori’ in terms of cost-community acceptable risk, and if the outbreak happens the system besides treatment, personal protection, and vector-reservoir control should also think in the psychological, social and economic consequences for individuals, families and collectives (refugees).